[postgis-tickets] [PostGIS] #2365: find_srid performance regression with large numbers of tables

[PostGIS]

#2365: find_srid performance regression with large numbers of tables
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 Reporter:  angrygoat  |       Owner:  pramsey      
     Type:  defect     |      Status:  new          
 Priority:  medium     |   Milestone:  PostGIS 2.0.4
Component:  postgis    |     Version:  2.0.x        
 Keywords:             |  
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Changes (by robe):

  * priority:  low => medium


Comment:

 I didn't even know that function existed and looks like it hasn't been
 touched in years. I was going to suggest marking it as immutable but
 noticed that is already set.  I would suggest bumping up the cost on it to
 say  500 or 1000 since its not a completely trivial function anymore (and
 the cost of 100 sounds a bit low). That will encourage it to cache more in
 shared mem so you'd then probably suffer the penalty only once in a while.

 Give that a try and if it works I think we can probably do at least that
 much since its definitely more costly than some of the other functions we
 have.

 I'm also wondering if the tables you have use constraints or typmod.  I
 would expect typmod ones to be much faster so you may consider converting
 your tables to typmod if you haven't already.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/2365#comment:3>
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